Filter tow bale, method and device for producing a filter tow bale and filter tow strips

ABSTRACT

The invention relates to a filter tow bale ( 2 ) from compressed filter tow, which is characterized in that the filter tow bale ( 2 ) comprises at least two separate filter tow strips ( 1, 1 ′) that are arranged together in layers.

The present invention relates to a filter tow bale with the features of the preamble of claim 1, a device and a method for producing a filter tow bale and a filter tow strip.

A filter tow bale of the type mentioned at the outset is produced and marketed, for example, by the Applicant.

To produce cigarettes, filters are used, which are manufactured from a band or a continuous strand of crimped cellulose acetate fibres, the so-called filter tow. During the production of filter tow, spun filaments of cellulose acetate are crimped in a stuffer box, the impressed crimping structure being fixed while passing through a dryer. Once the filter tow has been brought to a constant final moisture, it is loosely inserted in regular patterns in a plurality of metre-high cans. The loose tow layer is then compressed in bale presses to form a filter tow bale and finally packaged, the bale then being provided for further processing into filters.

A detailed description of the production process of filter tow is published in the essay CA Filter Tow für Cigarette Filter (CA filter tow for cigarette filters), Paul Rustemeyer, Macromolecular Symposia 208 (2004), 267-291.

Filter tow is processed into filter rods on a filter rod machine, on which the filter tow is bulked up as much as possible in a preparation part in order to develop its maximum filling force and is then gathered together to the format of the future cigarette filter and covered with paper. To bulk up the filter tow, the latter is drawn apart by means of compressed air-operated spreader nozzles and drawn by a system of drawing rollers with thread or screw surfaces. Thereafter, the spread filter tow is fed to a triacetin spray box, in that the acetate surface has solvent applied to it and is made tacky. In the formatting part of the filter rod machine, the filter tow band is gathered together and compressed to the cross section of the future filter rod. In this case, the filaments stick together and form a three-dimensional spatial network structure with the filter hardness desired for further processing and for the consumer.

To increase productivity, it is known, for example, from DE 43 20 317, which also goes back to the Applicant, to produce filter rods on double filter rod machines, in which two filter tow strands are processed in parallel and synchronously.

For a quality of the filter rods, which is as constant as possible, on the one hand, the filter tow strips should have similar properties and, on the other hand, run as uniformly as possible from the filter tow bale and also into the double filter rod machine.

The invention is based on the object of disclosing a filter tow bale, which allows a filter tow strip to run off as uniformly as possible and is suitable for use in a double filter rod machine. Furthermore, a device and a method for producing a filter tow bale and a filter tow strip for a filter tow bale of this type are to be disclosed.

According to the invention, this object is achieved with regard to the filter tow bale, by the subject of claim 1, with regard to the device, by the subject of claim 10, with regard to the method, by the subject of claim 18, and with regard to the filter tow strip by the subject of claim 21.

The invention has the advantage that spontaneous tension increases in the filter tow at the double filter rod machine are substantially avoided by the separate filter tow strips, so the density fluctuations connected therewith in the filter produced are minimised. Moreover, the filter tows may be produced and deposited simultaneously, so the properties thereof are similar or identical, which leads to an improved filter uniformity of the two strands during production on the double filter rod machine. Moreover, owing to the identical running lengths of the two filter tows, production drops are reduced. When there are different filter tow lengths, for example caused by running off from two different filter tow bales, increased waste and machine standstill times occur owing to the process of threading a new filter tow. The bale according to the invention also allows different filter tows to be inserted in the bale, so, for example, filter rod machines for special filters can be supplied with two different tows.

In a preferred embodiment, the at least two filter tow strips are heaped chaotically in insertion paths, in particular in substantially parallel paths or in acute-angled zigzag paths in the bale. This embodiment is based on the general idea of arranging the two filter tow strips aligned in the bale, the two strips forming a path pattern. The path pattern may, for example, be constructed from substantially parallel paths or from acute angled zigzag paths. The two filter tow strips are in each case chaotically heaped up along or within the paths. This means that in this embodiment, the chaotically heaped filter tow strips in each case have a preferred direction or a dominating direction, which extends path-wise in the bale. The paths thus in each case form imaginary side limits, within which the chaotically heaped filter tow strips are arranged. Because of the path-wise arrangement of the filter tow strips arranged layer-wise, the run-off behaviour of the strip from the bale is advantageously influenced.

The two filter tow strips may be arranged substantially in parallel paths next to one another and have a spacing, which is at least 0 cm and at most less than half the bale width. With a spacing of 0 cm, the filter tow strips or the paths, within which the filter tow strips are arranged, directly abut one another. The spacing between the parallel paths or the strips arranged in parallel may be >0 cm and a maximum of less than half the bale width. In a particularly preferred embodiment, at least two filter tow strips are arranged overlapping at least in portions and have an overlap region. The overlap region may have a degree of overlapping of 100% to >0%. Part regions of this overlap region are also possible. With a degree of overlapping of 100%, the filter tow strips or the paths within which the filter tow strips are arranged, lie completely one above the other.

In this case, the filter tow strips may be deposited in the bale in such a way that the strips are alternately arranged at the top and bottom. In this case, the strip arranged at the bottom in a path has, at the bale end, a turning point reversal in such a way that the strip firstly arranged at the bottom is arranged at the top after the turning point reversal on the return path. This produces a self regulation which prevents the strips running ahead, as the lower one of the two strips has a higher tension if it wishes to overtake the upper strip. Because of the arrangement of the strips one above the other, the lower one entrains the upper strip. After the turning point, when running back, the other strip is at the top, so the lower strip in turn then has the greater tension and entrains the strip arranged at the top. Overall, this produces a self regulation when the two strips run off from the bale.

Further preferred embodiments of the filter tow bale according to the invention are disclosed in the sub-claims.

With regard to the device for producing a filter tow bale, the invention is based on the idea of providing an inserting device, which cooperates with a can to deposit the filter tow, as well as means for simultaneously producing or providing at least two separate filter tow strips. In this case, the separate filter tow strips can be deposited together layer-wise in the can by a single or a double inserting device. Within the scope of the method according to the invention to produce a filter tow bale, in particular for processing in a double filter rod machine, at least two separate filter tow strips are produced or provided simultaneously, deposited together layer-wise in a can and pressed into bale form.

The filter tow bale according to the invention can easily be produced with the device according to the invention or the method according to the invention.

Preferred embodiments of the device according to the invention or the method according to the invention are given in the sub-claims.

A filter tow strip, which is particularly suitable for a filter tow bale according to the invention made of cross-linked and crimped filaments, has at least two partial strips, the partial strips being arranged at least partly, in particular completely, overlapping and being connected in the overlap region by applying a mechanical surface force. The run-off behaviour of the filter tow strip from the bale is positively influenced by the slight connection between the two partial strips, which are otherwise regarded as separate partial strips in the context of the invention.

Preferred embodiments of the invention are given in the sub-claims.

The invention will be described in more detail below with the aid of embodiments with reference to the accompanying schematic drawings, in which

FIG. 1 shows a schematic cross section of two filter tow strips in various combination possibilities A-E in the region of the inserter;

FIG. 2 shows a filter tow bale according to the invention while the filter tow strips run off according to a preferred embodiment;

FIG. 3 shows a filter tow bale according to the invention while the filter tow strips run off according to a further preferred embodiment; and

FIG. 4 shows a schematic view from above of the bale surface, the insertion track of two filter tow strips arranged one above the other being shown.

FIG. 1 schematically shows various variants A-E for combining two filter tow strips 1, 1′, the combination of the two filter tow strips 1, 1′ taking place before or during the insertion into a can. The filter tow located in the can is then compressed to form a double tow bale 2.

The combined filter tow strips shown in FIG. 1 are located in the inserter (not shown), in particular between the conveying roller of an inserter. This view is selected for reasons of clarity, as the arrangement of the two filter tow strips 1, 1′ relative to one another becomes particularly clear there. The arrangement of the two filter tow strips 1, 1′ in the inserter determines the arrangement of the two strips 1, 1′ in the filter tow bale 2. This means that the strips 1, 1′ arranged in parallel in the inserter according to view A are also arranged substantially parallel or in parallel paths in the filter tow bale 2. The strips 1, 1′ arranged one above the other according to the view B are also arranged one above the other in the bale or are deposited in paths arranged one above the other.

The depositing of the filter tow strips in the can and therefore the arrangement of the filter strips in the compressed bale takes place in paths. The paths are arranged in a predetermined pattern in this case, which is produced from the arrangement of the filter tow strips 1, 1′ in the inserter and the guidance of the filter tow strips 1, 1′ while being inserted. The filter tow strips 1, 1′ are arranged chaotically heaped within the paths. The paths follow a predetermined pattern. For example, the paths are arranged in parallel, completely overlapping or partly overlapping. The arrangement of the filter tow strips 1, 1′ or the associated paths will be described in more detail with the aid of variants A-E according to FIG. 1.

According to variant A in FIG. 1, the two filter tow strips 1, 1′ are arranged next to one another at a spacing. The strips 1, 1′ are in this case oriented parallel to one another, the spacing along the two strips 1, 1′ remaining substantially constant. The filter tow strips 1, 1′ may have a spacing of 0 cm with respect to one another, so the filter tow strips 1, 1′ touch one another directly. It is also possible for the spacing between the two filter tow strips 1, 1′ to correspond to half the width of the double tow bale 2, so one half of the double tow bale 2 is in each case associated with one filter tow strip 1, 1′. All the spacing values between 0 cm and half the bale width or less than half the bale width are also possible, in particular in the range of between 0.5 cm and 20 cm, between 5 cm and 20 cm or between 5 cm and 10 cm.

According to variant B, the two filter tow strips 1, 1′ are combined with one another completely overlapping lengthways. In this manner, a slight connection is formed over the entire strip width between the two filter tow strips 1, 1′, which allows a particularly uniform, synchronous running off of the filter tow strips 1, 1′ from the double tow bale 2 according to the invention. The two filter tow strips 1, 1′ may also, as shown in variant C, be combined partly overlapping one another, it being possible for the degree of overlapping of the two filter tow strips 1, 1′ to vary between 0% (variant A) and 100% (variant B). Even if a slight connection is established by the compression of the strips 1, 1′ arranged one above the other, the strips are regarded as separate strips 1, 1′ in the context of the invention.

According to a preferred variant D, the two filter tow strips 1, 1′ are arranged completely overlapping one another and folded in half lengthways, so the combined strip is substantially composed of four filter tow layers. After the insertion of the combined strip, with this variant, not only is a slight connection achieved between the two filter tow strips 1, 1′ by compressing the double tow bale 2 according to the invention, but also a slight connection of the two longitudinal halves of the first filter tow strip 1 with one another is achieved. By folding the combined strip, it is also achieved that a relatively narrow and easily handleable combined strip is formed from relatively wide filter tow strips 1, 1′. Variant E also offers this advantage, the two filter tow strips 1, 1′ being folded engaging in one another, i.e., the first filter tow strip 1 substantially has a degree of overlapping of 50% with the second filter tow strip 1′, the non-overlapping part of the first filter tow strip 1 being folded, so the latter rests on the overlapping part of the second filter tow strip 1′, in particular congruently with the overlap region. The outer, non-overlapping part of the second filter tow strip 1′ is likewise folded, so it comes to rest on the folded first filter tow strip 1. According to variant E, the connecting face between the two filter tow strips 1, 1′ is particularly large, so a relatively intensive and nevertheless easy to release connection is formed between the two filter tow strips 1, 1′ and therefore leads to a particularly advantageous, uniform and synchronous running off of the combined strip or the two filter tow strips 1, 1′ from the double tow bale 2 according to the invention.

FIGS. 2 and 3 in each case show a double tow bale 2 according to the invention, the two filter tow strips 1, 1′ according to variant A from FIG. 1 being arranged next to one another. A bale 2 with strips 1, 1′ arranged one above the other or paths according to variant B would be handled in accordance with FIG. 2. The spacing of the two filter tow strips 1, 1′ in FIG. 2 is less than half the bale width, while the spacing of the two filter tow strips 1, 1′ in the double tow bale 2 according to FIG. 3 corresponds to precisely half the bale width.

Furthermore, FIGS. 2 and 3 schematically show a run-off device 3 with guiding rings 4, by means of which the first filter tow strip 1 and the second filter tow strip 1′ run off from the bale 2 and are fed to a double filter rod machine (not shown). The two filter tow strips 1, 1′ are in each case arranged in a meandering shape in a plane in the double tow bale 2, the spacing of the two filter tow strips 1, 1′ with respect to one another being substantially constant. The embodiment according to FIG. 3 differs from FIG. 2 in that one half of the double tow bale 2 is associated in each case with one filter tow strip 1, 1′. When inserting the filter tow strips 1, 1′ in the bale 2, for example, the first filter tow strip 1, beginning in the centre of the bale 2, is inserted in a meandering shape in the direction of an outer edge in parallel paths, while the second filter tow strip 1′, beginning from an opposing outer edge, is inserted parallel to the first filter tow strip 1 in a meandering shape in the direction of the centre of the double tow bale 2. This means, that the two paths placed first have a spacing from one another, which corresponds to half the bale width. As the two filter tow strips 1, 1′ are arranged parallel to one another, the further respectively corresponding parallel paths are also spaced apart from one another by the amount of half the bale width.

In general, a filter tow bale 2 made of compressed filter tow comprises at least two separate filter tow strips 1, 1′, which are arranged layer-wise, preferably in the same layer. A filter tow bale with precisely two filter tow strips is also called a double tow bale. In general, the strips are in each case arranged together, in particular pairwise, in a layer and together form a plane. In this case, the area is regarded as a plane, which in the course of a laying cycle of the filter tow or the associated inserter, is passed over once. Within this plane it is possible, because of the heaping of the individual filter tow strips, for there to be a piling up of a plurality of filter tow portions one above the other, which, however, continue to lie in the plane passed over for each laying cycle.

The filter tow bale is built up of a plurality of corresponding layers or planes arranged one above the other, which are in each case formed by depositing the two filter tow strips together in a can with subsequent compression of the strips. In this case, the strips are configured continuously over a plurality of layers, ideally over the entire bale. The filter tow strips are arranged according to a predetermined pattern, which may vary according to the processing demands. The pattern is produced form the arrangement of the paths, in which the filter tow strips are deposited in the can and are also found again in the bale 2 after compression. The paths, in this case, correspond to the preferred directions of the filter tow strips, which are deposited within the paths heaped chaotically or statistically rearranged. An example of a corresponding heaping track is shown in FIG. 4. It can be seen in this that two filter tow strips 1, 1′ (dotted line/continuous line) are substantially arranged one above the other. The arrangement of the filter tow strips 1, 1′ one above the other does not mean that the two heaping tracks are arranged precisely one above the other. Rather, when depositing the two filter tow strips 1, 1′, the heaping track shown in FIG. 4 is produced, the two filter tow strips 1, 1′ having a common preferred direction. The insertion paths being produced from this preferred direction are arranged one above the other in the example according to FIG. 4 and have a degree of overlapping of 100%. With lower degrees of overlapping, for example with a degree of overlapping of 50%, the two paths, within which the heaping tracks of the two strips 1, 1′ are arranged, are offset with respect to one another in such a way that the heaping tracks substantially only overlap by half. It is clear that in the statistically rearranged heaps, larger or smaller degrees of overlapping are present in sections. However, it is important that, for example with the degree of overlapping of 50%, the heaping tracks or paths at least predominantly extend such that they are located approximately half one above the other.

The arrangement of the paths or heaping tracks in the bale is substantially determined by how the filter tow strips 1, 1′ are arranged in the inserter, in particular in the rollers of the inserter. This arrangement is shown in variants A-E according to FIG. 1. For example, in variant C (approximately 50% degree of overlapping) a corresponding arrangement of the heaping tracks or paths is produced in the compressed bale.

Apart from the parallel arrangement of the paths (overlapping or next to one another), it is also possible to arrange the paths to be diverging in such a way that the paths run apart from one another along their longitudinal extent. Moreover, an acute-angled zigzag arrangement is possible of the insertion paths.

The invention also comprises bales with more than two separate filter tow strips, for example with 3 or 4 strips. The parallel arrangement of the filter tow strips 1, 1′ means that the paths, in which the filter tow strips 1, 1′ are arranged, are arranged, in each case, directly adjacent pairwise or directly next to one another in the bale. The paths of the first and second filter tow strip 1, 1′ may be arranged overlapping, directly adjacent, i.e. abutting or parallel with a spacing from one another, in this case. Preferably, the two filter tow strips 1, 1′ are inserted in the bale 2 arranged overlapping, so they undergo a slight connection.

There are various possibilities for the simultaneous production or provision of the separate strips. It is possible to produce various independent strips in various independent crimping machines. Furthermore, various independent strips may be produced within a single crimping machine, the filter tow strips being guided in the crimping chamber at a spacing which is so great that a connection of the strips does not take place.

Furthermore, a connected strip may be produced, which is then separated into two individual strips. For this, various possibilities exist. The separation of the strip can either take place in the crimping machine, after the crimping machine, on the way to the inserting device or in the inserting device. Since the separation of the strip does not take place in the filter rod machine, the soiling of the filter rod machine by the fibre fractions being produced during the separation is avoided, so maintenance intervals of the filter rod machine can also be increased.

The simultaneously produced separate filter tow strips are deposited combined in the can by a single and a double, generally multiple inserting device (not shown). The inserting device is coupled for this purpose to a correspondingly programmed controller. The controller of the inserter allows the two filter tow strips to be deposited in the can in accordance with a predetermined pattern, for example in paths arranged one above the other.

The device for producing a filter tow bale, in addition to the above-described means for simultaneous production, also comprises a spinning mechanism for producing filaments, a crimping mechanism for crimping the filaments, a drier and the inserting device, which cooperates with the can for depositing the filter tow.

The separating device may comprise two guide rings arranged spaced apart transversely to the conveying direction of the filter tow strip and a guiding ring arranged upstream of the guide rings in the conveying direction. Alternatively or additionally, the separating device may comprise at least one separating wedge.

Instead of the simultaneous or synchronous production of the separate filter tow strips 1, 1′, a can may be loaded with two separate filter tow strips, which are provided in the form of two individual bales. Individual bales may, for example, be provided in the form of reject bales. Two strips are drawn off from the individual bales and together placed in a can.

It becomes clear from the above description that the separate filter tow strips 1, 1′ can be produced in a different manner, no restriction existing with regard to the number of filter tow strips, but more than two, for example three or four filter tow strips may be produced or provided. The particular advantages of the embodiments according to the invention emerge from the fact that the filter tow strips 1, 1′ are deposited together layer-wise in the can and compressed to form bales. These filter tow bales have at least two separate filter tow strips, which are arranged together layer-wise in the bale.

The insertion of the filter tow strips in the double tow bale such that the filter tow strips overlap furthermore offers the advantage that the filter tow strips undergo a slight connection with one another, which is brought about by compression, i.e. by the application of mechanical pressure. It has been shown that a loose connection of this type between the filter tow strips allows the strips to run off particularly uniformly and synchronously from the bale, so density fluctuations in the filter strand produced are avoided. To this extent, a filter tow strip connected from partial strips is also claimed, the relatively low strength of the connection being determined by the fact that the latter is produced by applying mechanical pressure to the partial strips, in particular during the compression of the bale.

LIST OF REFERENCE NUMERALS

-   1 first filter tow strip -   1′ second filter tow strip -   2 double tow bale -   3 run-off device -   4 guiding rings 

1. A filter tow bale made of compressed filter tow, wherein characterised in that the filter tow bale comprises at least two separate filter tow strips which are arranged layer-wise.
 2. A filter tow bale according to claim 1, wherein the at least two filter tow strips are arranged in the bale chaotically and are heaped in paths.
 3. A filter tow bale according to claim 1, wherein two filter tow strips in the filter tow bale are arranged substantially in parallel paths next to one another and have a spacing which is at least 0 cm and at most less than half the bale width.
 4. A filter tow bale according to claim 1, wherein the at least two filter tow strips are arranged overlapping at least in portions and have an overlap region.
 5. A filter tow bale according to claim 4, wherein the overlap region has a degree of overlapping of 90% to 10%.
 6. A filter tow bale according to claim 1, wherein the filter tow strips are folded into one another and in each case have a fold edge.
 7. A filter tow bale according to claim 6, wherein the fold edges are substantially arranged one above the other.
 8. A filter tow bale according to claim 6, wherein the fold edges are arranged substantially opposing.
 9. A filter tow bale according to claim 6, wherein the fold edge of one filter tow strip in each case encloses the longitudinal edge of the other filter tow strip.
 10. A device for producing a filter tow bale from a filter tow, comprising: a can for depositing the filter tow; an inserting device which cooperates with the can; means for simultaneously producing at least two separate filter tow strips together, layer-wise, in the can.
 11. A device according to claim 10, wherein means for simultaneously producing at least two filter tow strips comprises a plurality of spinning machines or a multiple spinning machine.
 12. A device according to claim 10, wherein the means for simultaneously producing at least two filter tow strips comprises a plurality of crimping machines or a multiple crimping machine which is loaded with two separate filter tow strips.
 13. A device according to claim 12, wherein the means for simultaneously producing at least two filter tow strips further comprises at least one separating device for separating the filter tow strips which is arranged downstream of the crimping machine.
 14. A device according to claim 13, wherein the separating device comprises at least two guide rings arranged spaced apart and transverse to a conveying direction of the filter tow strip.
 15. A device according to claim 14, wherein a guiding ring is arranged upstream of the two guide rings in the conveying direction.
 16. A device according to claim 13, wherein the separating device comprises at least one separating wedge arranged downstream of the crimping machine.
 17. A device according to claim 13, wherein the inserting device comprises means for depositing the at least two filter tow strips together in the can.
 18. A method for producing a filter tow bale in a double filter rod machine, comprising the steps of: producing in which at least two separate filter tow strips simultaneously; depositing the at least two separate filter tow strips together, layer-wise, in a can; and pressing the deposited filter tow strips into a bale form.
 19. A method according to claim 18, wherein the depositing step comprises depositing the filter tow strips in an overlapping manner at least in portions in the can.
 20. A method according to claim 18, wherein the producing step comprises separating a common filter tow strip, the separating taking place in or after action by a crimping machine or before or during the step of depositing the at least two separate filter tow strips in the can.
 21. A filter tow strip made of cross-linked and crimped filaments, comprising at least two partial strips, arranged at least partly, in an overlapping manner and connected in an overlap region by a mechanical surface force.
 22. A device for producing a filter tow bale from a filter tow, comprising: A can for depositing the filter tow; an inserting device which cooperates with the can; means for providing at least two separate filter tow strips together, layer-wise, in the can. 